Protective role for caspase-11 during acute experimental murine colitis

Area of Science:

• Immunology
• Gastroenterology
• Cell Biology

Background:

• The noncanonical inflammasome, activated by caspase-11, produces IL-1β and IL-18, important in host defense and septic shock.
• Its role in acute intestinal inflammation, specifically in dextran sodium sulfate (DSS)-induced colitis, is not well understood.

Purpose of the Study:

• To investigate the role of the noncanonical inflammasome and caspase-11 in DSS-induced experimental colitis.
• To elucidate the mechanisms by which caspase-11 influences intestinal inflammation and epithelial barrier function.

Main Methods:

• Utilized caspase-11 knockout (caspase-11(-/-)) mice and DSS administration to model acute colitis.
• Assessed susceptibility to DSS, measured IL-18 production, and evaluated intestinal epithelial cell proliferation and death.
• Investigated the signaling pathways involved in caspase-11 production in intestinal epithelial cells.

Main Results:

• Caspase-11(-/-) mice exhibited enhanced susceptibility to DSS-induced colitis.
• Impaired IL-18 production in caspase-11(-/-) mice correlated with reduced intestinal epithelial cell proliferation and increased cell death.
• A novel type II IFN-dependent, type I IFN-TRIF-independent pathway was identified as necessary for in vivo caspase-11 production.

Conclusions:

• IFN-γ-mediated caspase-11 expression plays a critical role in maintaining intestinal epithelial barrier integrity during acute experimental colitis.
• Caspase-11 and its downstream effects on IL-18 are essential for host defense in the context of intestinal inflammation.